In many electronic devices there is a need to conserve power. In particular, in battery operated hand held devices, the amount of power available is limited. One technique, frequently used to conserve power, is to have a low power mode. Such a low power mode is frequently referred to as a “sleep mode”.
Generally, when a device is in a sleep mode, many of the components in the device are deactivated. Only those components are active that are necessary so that the device can resume a fully operational state without any significant delay. Devices that have a sleep mode must have some mechanism to return the device to an operations state from the sleep power mode. Returning a device to an operational mode from a sleep mode is generally referred to as waking the device.
There are a variety of existing mechanisms for waking electronic devices from a sleep mode. The simplest is a mechanical switch or button, that when pressed, wakes the device. Other known devices include optical or mechanical motion sensors. Such motion sensors can, for example, be used to wake a battery operated wireless mouse when the mouse is moved.
Existing devices for waking hand help battery operated devices have a variety of disadvantages. For example, a button or switch requires a specific physical action on the part of the operator to press the button or switch. Many motion sensors require additional hardware. Finally, many of the existing devices consume what may be a significant amount of power for a very low power device.
Described below are an improved method, system and device for waking a hand held electronic device.